Degenerative neurological disorder is a disorder in which degenerative changes in the nervous system of the central nervous system cause various symptoms due to the motor and sensory impairment and inhibition of functions such as memory, learning, and computational reasoning. Degenerative neurological disorders occur in a specific part of the nervous system, causing symptoms such as dementia, extrapyramidal abnormality, cerebellar abnormality, sensory disturbance, and movement disorder. In some cases, many parts may be affected at the same time, resulting in complex symptoms. The diagnosis is based on the clinical manifestations of the patient. In this case, it is difficult to diagnose since various other disorders show common clinical symptoms (Soc. Sci. Med. Vol. 40(6), pp. 847-858, 1995).
Dementia, one of the degenerative neurological disorders, is a disorder with general impairment of systemic function, including memory impairment and loss of judgment. Dementia is a geriatric disease: before age 50, its symptoms rarely occur, but after age 60, its frequency of occurrence is gradually increased. As the elderly population increases due to the development of medical technology and quality of life, the number of affected population is rapidly increased not only in Korea but also globally. The number of dementia patients aged 65 years or older registered in 2008 is 421,000, accounting for 8.4% of the total population of the elderly population. In 2030, the number is expected to be 1,135,000, being greater than 9.6% of the total elderly population. In 2008, the Ministry of Health and Welfare researched for the prevalence of dementia and found that there are various onsets of dementia: from among domestic dementias, about 70% are dementia of Alzheimer type, about 25% are dementia of Vascular type, 5% or less are other alcoholic dementia and Parkinson's disease dementia.
Alzheimer disease (AD), the major onset form of dementia, is characterized by two distinct lesions: one is formation of neurofibrillary tangles in the cells caused by hyperphosphorylation and aggregation of tau proteins in neurons of the cortex and hippocampus, and the other one is a plaque formed outside the cells by the aggregation of amyloid β-1/42.
Although the cause of Alzheimer's disease has not yet been clarified, tangles, plaques, or precursors, which are the aggregation form of two proteins involved in aggregation, is deposited on neuronal cells responsible for brain memory and recognition, causing neuronal dysfunction and death, causing Alzheimer.
Genetic and environmental factors play a role in the pathogenesis of senile dementia. Genetic associations include mutations of β-amyloid precursor protein (APP) gene, presenilin-1 (PS1) gene, and presenilin-2 (PS2) gene. These mutations were confirmed in a households suffering from dementia. APP, PS1, PS2, etc. are known to increase the production of β-amyloid (Aβ) precipitated in plaques. As described above, APP, PS1, and PS2 are critical in the pathogenesis of senile dementia, and are currently the subject to be considered in developing new drugs.
Korean Patent Publication No. 2014-0042148 discloses a composition for preventing or treating a degenerative neurological disorder including a bioactive peptide as an active ingredient, Japanese Patent Registration No. 5221633 discloses low molecular weight peptides for the treatment of Alzheimer's disease and other β-amyloid protein fibrillogenesis disorder, and U.S. Patent Publication No. 2014-0271690 discloses a peptide vaccine for the prevention of Alzheimer-type dementia and immunotherapy. However, there has not yet been disclosed a composition for the prevention, improvement, or treatment of a neurological disorder containing an adiponectin receptor-activating novel peptide as an active ingredient according to the present disclosure.